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N‐Annulated Perylene‐Substituted and Fused Porphyrin Dimers with Intense Near‐Infrared One‐Photon and Two‐Photon Absorption
Author(s) -
Luo Jie,
Lee Sangsu,
Son Minjung,
Zheng Bin,
Huang KuoWei,
Qi Qingbiao,
Zeng Wangdong,
Li Gongqiang,
Kim Dongho,
Wu Jishan
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201405574
Subject(s) - porphyrin , photochemistry , chromophore , dimer , perylene , excited state , fluorescence , ultrafast laser spectroscopy , absorption (acoustics) , chemistry , femtosecond , absorption spectroscopy , two photon absorption , vibronic coupling , materials science , spectroscopy , molecule , atomic physics , organic chemistry , optics , laser , physics , quantum mechanics , composite material
Fusion of two N ‐annulated perylene (NP) units with a fused porphyrin dimer along the S 0 –S 1 electronic transition moment axis has resulted in new near‐infrared (NIR) dyes 1 a / 1 b with very intense absorption (ε>1.3×10 5 M −1 cm −1 ) beyond 1250 nm. Both compounds displayed moderate NIR fluorescence with fluorescence quantum yields of 4.4×10 −6 and 6.0×10 −6 for 1 a and 1 b , respectively. The NP‐substituted porphyrin dimers 2 a / 2 b have also been obtained by controlled oxidative coupling and cyclodehydrogenation, and they showed superimposed absorptions of the fused porphyrin dimer and the NP chromophore. The excited‐state dynamics of all of these compounds have been studied by femtosecond transient absorption measurements, which revealed porphyrin dimer‐like behaviour. These new chromophores also exhibited good nonlinear optical susceptibility with large two‐photon absorption cross‐sections in the NIR region due to extended π‐conjugation. Time‐dependent density functional theory calculations have been performed to aid our understanding of their electronic structures and absorption spectra.